Method and apparatus for producing fibers



EJR. POWELL 2,884,659

- METHOD AND APPARATUS FOR PRODUCING FIBERS May 5, 1959' Filed Nov. 9, 1956 mp0 w n m 1% United States Patent C) NIETHOD AND APPARATUS FOR PRODUCING FIBERS Edward R. Powell, North Plainfield, N.J., assignor to Johns-Manville Corporation, New York, N.Y., a corporation of New York Application November 9, 1956, Serial No. 621,296 Claims. (Cl. 18-2.5)

This invention relates to the manufacture of fibers from mineral wool forming material and the like, and more particularly, to an improved method and apparatus for producing such fibers.

In the production of mineral wool and the like, heretofore, various processes have been developed for converting molten mineral material, or material having similar characteristics, into fibrous form in a number of ways, including the conventional method of subjecting a stream of molten material, such as slag, rock, glass, mixtures thereof, and other heat liquefiable materials which may be drawn out into fibrous form, to the shredding. action of a high pressure steam jet, or other gaseous fluid, which shreds the stream into a multiplicity of fibers. It has also been proposed to employ a method in which molten mineral matter is distributed in the form of streams flung tangentially from the periphery of a rotating distributor rotor; these streams being subjected to the blast or blasts of gaseous fluid and becoming attenuated into fibers.

While these methods have been successful in various degrees in producing commercially fibers of varying quality, nevertheless, none has been successful as desirable in converting a desirably high proportion of the stream of the molten material into fibers, with a minimum of unfiberized droplets or shot content. These droplets or pieces of shot, usually found attached to or loosely embedded between the fibers, are solidified particles of slag or molten material which were either partially fiberized or which failed to be attenuated during the fiberization process. The formation of these particles is believed to take place during the shredding operation of the stream of molten slag, from which particles the fibers are finally developed. It is therefore of utmost importance that the attenuation of these particles be continued until the particles are completely formed into fibers, if clean, long and fine fibers are to be obtained.

Accordingly, the main purpose of the present invention is to provide a new and improved process and apparatus fiber yield and which will produce finer fibers than in the prior practice, in which fibers the droplet or shot content is greatly reduced.

It is further a purpose of this invention to provide an improved method and apparatus wherein a stream of molten matter'is subjected to several steps of a fiberization process, thereby insuring higher recovery by thorough attenuation of practically all of the fiber forming droplets.

A still further purpose of the present invention is the provision of improved means for accomplishing fiberization from several streams in fairly close relation and which may also be utilized for effecting a thorough binder mixing during operation of the fiberizing process.

fiberizing high velocity jets of a gaseous fluid are arranged in a novel manner in cooperation with distributor means, wherein molten matter first subjected to the shredding action of the jets is passed in the form of fibers and 2,324,140, to Dobak et 211., issued July 13, 1943.

' ice fiber forming droplets through a deflecting high velocity blast of gaseous fluid for removing the free fibers, while the droplets having a greater inertia are projected against the distributor means on which the droplets are impinged, and then flung or projected by the action of the centrifugal force in the path of the high velocity deflecting jet to become attenuated, thereby producing long and fine fibers for improved coherence and insulating properties.

These and other features of the present invention are described in detail in connection with the accompanying drawing, wherein like numerals designate like parts, and in which:

Fig. 1 is a top plan view of an apparatus embodying the present invention;

Fig. 2 is a front elevation of the apparatus of Fig. 1;

Fig. 3 is a view in perspective, on an enlarged scale, of one of the nozzles employed in the apparatus of Fig. 1;

Fig. 4 is a view similar to that of Fig. 3, but of the other nozzle employed in the apparatus of Fig. 1; and

Fig. 5 is a fragmentary horizontal section, on an enlarged scale, of a distributor disc or rotor of the apparatus of Fig. 1, illustrating the formation of fibers during operation. W

Referring now in detail to the drawing, the'apparatus illustrated in the drawing as an embodiment of the present invention comprises a rotary distributor disc or rotor 10, mounted for rotation about a preferably horizontal axis upon a shaft 12. The shaft 12 may be supported for rotation in any suitable manner (not shown), as well known in the art. The distributor disc 10 is formed of a substantially conical or frusto-conical surface 14 which is suitably provided with a succession of concentric annular grooves 16. These grooves 16 are preferably V- shaped in cross-section and of relatively small uniform size for preventing creeping of the soft slag deposited on the disc 10 radially outwardly thereon, and for deflecting droplets or particles impinged on the surface 14 into the path of a blast of gaseous fluid as hereinafter described. The distributor rotor 10 may be of 10 to 12 inches in diameter and may preferably revolve at about 6000 to 8000 rpm.

A melting furnace 18, which may be of any suitable type, such as the cupola illustrated, is provided with a discharge trough 20 from which a stream of molten matter 22 is drawn from the furnace 18 and discharged into position for fiberization in front of the disc 10 to one side of the center axis of the disc 10 and in horizontally spaced relation with respect to the distributor disc 10.

In accordance with the instant invention, a nozzle 24 is positioned in front of the rotor disc 10 and adjacent to the stream 22, whereby the stream 22 is disposed between the distributor disc 10 and the nozzle 24. The nozzle 24 for fiberizing molten material which will provide a greater 3' i is Preferably fofmfid 10 include tW0 upstanding Sections or wings 26 and 28, the adjacent inner walls of which diverge upwardly in substantially a V-shape. Each section 26 and 28 includes an elongated discharge orifice 30 formed by preferably parallel-sided slots communicatingwith the hollow interior of the wing and through which the stream, compressed air, or other fluid issued as a high velocity jet 31 to perform the shredding operation. The nozzle 24 may be of the type disclosed in U.S. Patent No. The nozzle 24 may discharge approximately 1000 to 1800 lbs. per hr. of steam at lbs. per sq. in., while the stream of the molten slag 22 may be discharged at the rate of 2000 to 2400 lbs. per hr. at 2400 to 2600 degrees F. It

Inv accordance with the present invention, a plurality of should also be noted that more than one stream of the molten material 22 may be used, even though, only one is illustrated in the drawing. If more than one stream is used, the streams should be in very close relation so as to 7 fall in front of the nozzle 24. For example, a stream of,

3 molten matter 22 may fall in front of each orifice 30 of the nozzle 24.

The stream of molten matter 22 falling between the jets, as illustrated, and closely adjacent and substantially parallel to one of the orifices 30 is completely surrounded by the steam and may be shredded by the jets of the gaseous fluid projected at substantially right angles thereto and at an acute angle to the rotor disc 10, into a great multiplicity of droplets from which fibers at first form in trailing formation, as shown in Fig. 5. The action of the high velocity blasts 31 of the gaseous fluid may then draw the fibers ahead of the droplets due to the additional surface now exposed, as also shown in Fig. 5. The fibers thus formed may now be deflected to one side of the droplet, as shown to the right of the droplets in Fig. 5, so that any free fibers, and fibers which may be detached from the droplets, may be further deflected laterally of the blasts 31 and to one side generally radially outwardly and away from the distributor disc by the deflecting action of a high velocity blast 32 of a second nozzle 33 projected in a direction converging upon the blasts 31, which also converge upon each other beyond the streams of the molten material 22. The free fibers thus deflected from the path of the blasts 31 are further aspirated into a collecting chamber (not shown) by additional blowing or suction means, as is well known to the one skilled in the art, to be collected, while droplets with fibers still attached thereto and unfiberized droplets (the droplets in both forms, separately and collectively, being referred to in the claims as fiber forming droplets), due to their greater inertia, will impinge onto the surface 14 of the distributor disc It) by the pressure of the blasts 31 exerted thereon, whereon they are subjected to the action of centrifugal force.

The droplets impinged against the grooved surface 14 of the distributor disc 10 are then flung from the productive portion of the disc or rotor 10, usually about one third of the rotor disc area, as the right lower portion of the disc 10, by the action of the centrifugal force in planes corresponding to the grooves 16 and extending substantially radially outwardly with respect to the tapering or sloping surface 14 of the disc 10. That portion of the material flung from the disc 10 in the region adjacent the nozzle 24 is then thrown into the path of the high velocity blast 32 of a jet of gaseous fluid discharged from the second nozzle 33. The nozzle 33 is preferably formed with an elongated discharge orifice 34 and is positioned closely adjacent to the surface 14 of the disc 10, and to one side of the nozzle 24, radially inwardly thereof with respect to the disc 10, as shown in Figs. '1 and 2. The blast 32 discharged from the orifice 34 of the nozzle 33 is arranged to extend substantially parallel to and in horizontally spaced relation with respect to the sloping surface 14 of the disc 10. By reason of this arrangement, any of the still unfiberized droplets and partially fiberized droplets projected or flung from the disc surface 14 into the path of the blast 32, are further attenuated thereby, and also by the action of the converging blasts 31 and 32 of both nozzles 24 and 33, respectively, which exert a pull at a high velocity on the incipient fibers of the droplets.

In order to prevent an excessively thick superposed, incandescent layer of molten material or slag from building up on the rotor disc surface 14, say not more than 5 in., a stripping or scraping roll 36 may be provided, which is formed of a frusto-conical shape and which is arranged to contact the layer of the soft slag on the sloping surface 14, as shown in Figs. 1 and 2. The surface of the roll 36 may also be knurled, as indicated at '38, so as to act as a surface conditioner by roughening the slag layer surface to a texture of up to about in., on the disc surface 14, from which roughened slag fibers may more readily be drawn by the combined actions of the blast 32 and the centrifugal force of the disc '10.

It will also be understood that a binder, if in liquid form, such as drying oil type or phenolic resin binder, may be introduced into the steam or any other fluid of the deflecting jet 32, thereby being disposed and deposited on the suspended fibers. The collection of the fibers thus formed may be effected, as previously mentioned above, in any suitable manner, as by aspiration into a collection chamber, as now used for blown or spun mineral wool.

The present invention has been described in detail above for purposes of illustration only, and is not intended to be limited by this description or otherwise, except as defined in the appended claims.

What I claim is:

1. The method of forming fibers which comprises discharging molten material into the path of a high velocity blast of gaseous fluid, forming fibers and fiber forming droplets from said material by the action of said blast, subjecting the fibers and fiber forming droplets do a deflecting high velocity blast of gaseous fluid for removing the free fibers from the fiber forming droplets, and intercepting the fiber forming droplets by a rotor.

2. The method as defined in claim 1, including the further step of flinging the molten material from the rotor in the form of fiber..

3. The method as defined in claim 1, including the further step of flinging the molten material from the rotor into the path of the deflecting blast for further attenuating the material into fibers.

4. The method as defined in claim 1, including the further steps of discharging the molten material from the rotor, and intercepting the discharged molten material by the deflecting blast.

5. The method as defined in claim 1, wherein the molten material in the form of droplets intercepted by the rotor forms an incandescent layer thereon, and including the further steps of roughening the surface of the incandescent layer on the rotor, discharging the molten material from the rotor, and subjecting the discharged material to the deflecting blast for attenuating the material into fibers.

6. Apparatus for converting molten raw material into fibers comprising a rotor supported for rotation about an axis, means for directing a fiberizing fluid blast toward said rotor, means for delivering a stream of .the molten raw material into said fiberizing fluid blast, said fiberizing fluid blast being adapted to convert said stream into fibers and fiber forming droplets and to propel said fiber forming droplets against said rotor, means for directing a deflecting fluid blast transversely of said fiberizing fluid blast to deflect said fibers away from said rotor, said deflecting fluid blast being of insufficient force to prevent said fiber forming droplets from reaching said rotor, and means for rotating said rotor.

7,. Apparatus for converting molten raw material into fibers comprising a rotor supported for rotation about an axis, a first nozzle positioned adjacent but spaced from said rotor, said first nozzle directing a fiberizing fluid blast toward said rotor, means for delivering a stream of molten raw material into said fiberizing fluid blast, said fiberiz: ing fluid blast being adapted to convert said stream into fiber and fiber forming droplets and to propel said fiber forming droplets against said rotor, a second nozzle positionedbetween said first nozzle and said rotor, said second nozzle directing a deflecting fluid blast transversely of said fiberizing fluid blast to deflect said fibers away from saidrotor, said deflecting fluid blast being ofinsufiicient force to prevent said fiber forming droplets from reaching said rotor, and means for rotating said rotor.

8. Apparatus for converting molten raw material into fibers comprising a rotor supported for rotation about an axis, means for directing a fiberizing fluid blast toward said rotor, means for delivering a stream of molten raw material into said fiberizing fluid blast, said fiberizing fluid blast being adapted to convert said stream into fibers and fiber forming droplets and to propel said fiber forming droplets against said rotor, means for directing a deflecting fluid blast transversely of said fiberizing fluid blast to deflect said fibers away from said rotor, said deflecting fluid blast being of insufficient force to prevent said fiber forming droplets from reaching said rotor to form an incandescent layer thereon, a stripping roller for contacting said incandescent layer, said stripping roller being adapted to roughen the surface thereof and to limit the thickness of said incandescent layer, and means for rotating said rotor.

9. Apparatus for converting molten raw material into fibers comprising a rotor supported for rotation about an axis, said rotor having a frusto-conical surface, said frusto-com'cal surface having a plurality of concentric annular grooves formed therein, a first nozzle positioned adjacent but spaced from said rotor, said first nozzle directing a fiberizing gaseous blast toward said frustoconical surface of said rotor, means for delivering a stream of molten raw material into said fiberizing gaseous blast, said fi'berizing gaseous blast being adapted to convert said stream into fibers and fiber forming droplets and to propel said fiber forming droplets against said frusto-conical surface, a second nozzle positioned between said first nozzle and said rotor, said second nozzle directing a deflecting gaseous blast transversely of said fiberizing gaseous blast to deflect the fibers away from said frusto-conical surface, said deflecting gaseous blast being of insuflicient force to prevent said fiber forming droplets from reaching said frusto-conical surface, and means for rotating said rotor.

10. Apparatus for converting molten raw material into fibers comprising a rotor supported for rotation about an axis, said rotor having a frusto-conicall surface, said frusto-conical surface having a plurality of concentric annular grooves formed therein, a first nozzle positioned adjacent but spaced from said rotor, said first nozzle directing a fiberizing gaseous blast toward said frustoconical surface of said rotor, means for delivering a stream of molten raw material into said fiberizing gaseous :blast, said fiberizing gaseous blast being adapted to convert said stream into fibers and fiber forming droplets and to propel said fiber forming droplets against said frusto-conical surface, a second nozzle positioned between said first nozzle and said rotor, said second nozzle directing a deflecting gaseous blast transversely of said fiberizing gaseous blast to deflect said fibers away from said frusto-conical surface, said deflecting gaseous blast being of insufficient force to prevent said fiber forming droplets from reaching said frusto-conical surface to form an incandescent layer on the fnusto-conical surface of said rotor, a stripping roller for contacting said incandescent layer, said stripping rol'ler being adapted to roughen the surface thereof and to limit the thickness of said incandescent layer, and means for rotating said rotor.

References Cited in the file of this patent UNITED STATES PATENTS Powell Dec. 4, 1951 Koehler Mar. 31, 1953 

